1 /* $OpenBSD: readdir.c,v 1.22 2015/09/12 13:34:22 guenther Exp $ */ 2 /* 3 * Copyright (c) 1983, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <dirent.h> 32 #include <errno.h> 33 #include "telldir.h" 34 #include "thread_private.h" 35 36 /* 37 * get next entry in a directory. 38 */ 39 int 40 _readdir_unlocked(DIR *dirp, struct dirent **result) 41 { 42 struct dirent *dp; 43 44 *result = NULL; 45 for (;;) { 46 if (dirp->dd_loc >= dirp->dd_size) { 47 dirp->dd_loc = 0; 48 dirp->dd_size = getdents(dirp->dd_fd, dirp->dd_buf, 49 dirp->dd_len); 50 if (dirp->dd_size == 0) 51 return (0); 52 if (dirp->dd_size < 0) 53 return (-1); 54 } 55 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc); 56 if ((long)dp & 03 || /* bogus pointer check */ 57 dp->d_reclen <= 0 || 58 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) { 59 errno = EINVAL; 60 return (-1); 61 } 62 dirp->dd_loc += dp->d_reclen; 63 if (dp->d_ino == 0) 64 continue; 65 dirp->dd_curpos = dp->d_off; 66 *result = dp; 67 return (0); 68 } 69 } 70 71 struct dirent * 72 readdir(DIR *dirp) 73 { 74 struct dirent *dp; 75 76 _MUTEX_LOCK(&dirp->dd_lock); 77 _readdir_unlocked(dirp, &dp); 78 _MUTEX_UNLOCK(&dirp->dd_lock); 79 80 return (dp); 81 } 82 DEF_WEAK(readdir); 83